Rich and beautiful as it is, purple madder cannot be called brilliant; while Mars violet is, of course, ochrous. Unlike green and orange, therefore, purple can point to no original pigment at once vivid and durable: as regards purple, brilliancy implies a semi-stability that borders more or less closely on fugacity. Until the advent of a perfect palette, however, brilliancy and semi-stability will doubtless hold their own. Their present popularity may be seen by a glance at the lists of artist-colours--lists compiled, be it remembered, in obedience to the law of demand and supply. If art were really so much honoured as some of its disciples pretend, none but durable colours would be employed. In our opinion, if a picture be worth painting at all, it is worth painting with permanent pigments; but many evidently think otherwise. Deploring an error neither flattering to the craft they practise nor to themselves, we would urge such to bear in mind this axiom, semi-stable pigments become fugitive when used in thin washes. Even in body they do not preserve their primitive hue, but in glazing and the like, their colour altogether flies or is wholly destroyed. It is this semi-stability, recommended to the thoughtless and indifferent by the beauty which generally accompanies it, that is the bane of modern art. Even our greatest painters have yielded to its fascination. Who has not gazed upon one of Turner's fading pictures with still more of sadness than enjoyment, that anything so grand, so beautiful, so true, should slowly but surely be passing away? A feeling akin to pity is conjured up at the sight of the helpless wreck, abandoned amid the treacherous materials employed, and sinking deeper and deeper. Mournful, indeed, is that mighty ruin of mind amid matter; mournful the thought that in years to come, the monument sought for will not be found. FOOTNOTES: [A] A talent of money, _i.e._, a talent's weight of silver, was equal to nearly £244. CHAPTER XIV. ON THE TERTIARY, CITRINE. Citrine, or the colour of the citron, is the first of the tertiary class of colours, or ultimate compounds of the primary triad, yellow, red, and blue; in which yellow is the archeus or predominating colour, and blue the extreme subordinate. For citrine being an immediate compound of the secondaries, _orange_ and _green_, of both which yellow is a constituent, the latter colour is of double occurrence therein, while the other two primaries enter singly into its composition. The mean or middle hue comprehends eight blue, five red, and six yellow, of equal intensities.